1 /*
2 * rational numbers
3 * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22 /**
23 * @file
24 * rational numbers
25 * @author Michael Niedermayer <michaelni@gmx.at>
26 */
27
30
34
36 int64_t num, int64_t den, int64_t max)
37 {
39 int sign = (num < 0) ^ (den < 0);
41
42 if (gcd) {
43 num =
FFABS(num) / gcd;
44 den =
FFABS(den) / gcd;
45 }
46 if (num <= max && den <= max) {
48 den = 0;
49 }
50
51 while (den) {
52 uint64_t x = num / den;
53 int64_t next_den = num - den * x;
54 int64_t a2n = x *
a1.num + a0.
num;
55 int64_t a2d = x *
a1.den + a0.
den;
56
57 if (a2n > max || a2d > max) {
58 if (
a1.num) x = (max - a0.
num) /
a1.num;
60
61 if (den * (2 * x *
a1.den + a0.
den) > num *
a1.den)
63 break;
64 }
65
68 num = den;
69 den = next_den;
70 }
72
73 *dst_num = sign ? -
a1.num :
a1.num;
75
76 return den == 0;
77 }
78
80 {
83 b.
den * (int64_t) c.
den, INT_MAX);
85 }
86
88 {
90 }
91
96 b.
den * (int64_t) c.
den, INT_MAX);
98 }
99
101 {
103 }
104
106 {
108 #define LOG2 0.69314718055994530941723212145817656807550013436025
109 int exponent;
110 int64_t den;
113 if (fabs(d) > INT_MAX + 3LL)
115 exponent =
FFMAX( (
int)(log(fabs(d) + 1e-20)/
LOG2), 0);
116 den = 1LL << (61 - exponent);
117 // (int64_t)rint() and llrint() do not work with gcc on ia64 and sparc64
119 if ((!a.
num || !a.
den) && d && max>0 && max<INT_MAX)
121
123 }
124
126 {
127 /* n/d is q, a/b is the median between q1 and q2 */
128 int64_t
a = q1.
num * (int64_t)q2.
den + q2.
num * (int64_t)q1.
den;
129 int64_t
b = 2 * (int64_t)q1.
den * q2.
den;
130
131 /* rnd_up(a*d/b) > n => a*d/b > n */
133
134 /* rnd_down(a*d/b) < n => a*d/b < n */
136
138 }
139
141 {
142 int i, nearest_q_idx = 0;
143 for (i = 0; q_list[i].
den; i++)
144 if (
av_nearer_q(q, q_list[i], q_list[nearest_q_idx]) > 0)
145 nearest_q_idx = i;
146
147 return nearest_q_idx;
148 }
149
150 #ifdef TEST
152 {
161 if (d > 0) d = 1;
162 else if (d < 0) d = -1;
163 else if (d != d) d = INT_MIN;
164 if (c != d)
170 }
171 }
172 }
173 }
174
178 continue;
183 continue;
185 continue;
186 for (start = 0; start < 10 ; start++) {
188 int i;
189
190 for (i = 0; i<100; i++) {
193 if (
FFABS(acc - exact) > 2) {
196 return 1;
197 }
198 }
199 }
200 }
201 }
202 }
203 }
204 return 0;
205 }
206 #endif